1. Field of the Invention
The present invention relates generally to lamps and more particularly to lamps that use fossil or hydrocarbon fuels. The invention also relates to devices for dispensing volatile substances.
2. Description of Related Art
Portable lamps, lanterns, and flashlights that use hydrocarbon or fossil fuels such as butane are known. One such type of lamp is described in U.S. Pat. No. 3,843,311 to Nelson and U.S. Pat. No. 4,321,656 to Gruver, Jr., the teachings of both of which are incorporated by reference herein. This type of lamp generally has a fuel source such as a compartment or container that holds fuel in a liquid or gaseous state. When it is desired to use the lamp, either a person may provide a localized flame source (e.g., a match) to an exit port of the fuel to ignite the fuel, or the lamp may be provided with an internal igniter such as that described in U.S. Pat. No. 3,843,311 (e.g., a piezoelectric igniter). Because of their ease of use and portability, these lamps are commonly used for camping and other outdoor-related activity where access to electricity is significantly limited. Portable flashlights of this nature are described in U.S. Pat. No. 4,975,044 to Diederich and U.S. Pat. No. 4,475,882 to Gruner, the teachings of both of which are incorporated by reference herein.
In such outdoor environments, there is generally no protection from mosquitos and other insects. For example, if a person is camping or performing work in an outdoor setting, the person is subject to being bitten by insects, an often painful and sometimes dangerous process. Moreover, it is known that insects are commonly attracted to light sources. Thus, the use of a portable lamp or lantern in an outdoor setting may exacerbate the insect problem.
A variety of portable devices for dispensing volatile substances into the air are available. Such volatile substances most commonly are either insect control active ingredients or air treatment materials, such as air fresheners. Many of these portable devices utilize a battery-powered fan to evaporate volatilizable materials, without the use of heat.
Devices that utilize heat to evaporate or volatilize an active ingredient or other volatile substance are also well known in the art. However, many of these devices require access to house current or the like for the electrical power required to energize the heater. Consequently, the devices are not portable beyond the length of their power cords from the electrical receptacle into which they must be plugged.
Flames are another common source of heat for dispensing volatile substances. For example, scented candles and lighted wicks of various sorts underneath potpourri kettles are traditional devices for air freshening or air scenting. Citronella candles are an example of the same technique applied to insect control. Similarly, mosquito coils use combustion heat to volatilize or otherwise distribute insect control active ingredients into the area surrounding the device. A mosquito coil is a structure of punk or other slow-burning material that is either self-supporting or that is printed onto a substrate. The punk is lighted at one end to slowly burn, like incense, distributing with its smoke or by volatilization an insect control ingredient.
Other devices burn liquid fuel, most commonly alcohol, to generate heat for vaporizing insect control active ingredients. The device distributed by La Reina Enterprises of Falmouth, Mass. under the name "Skeeter Eater" evaporates insect repellent from an impregnated pad by heating the pad with a hot metal catalyst mesh fueled with alcohol. Similar products, sometimes using a simple alcohol flame instead of a metal catalyst mesh, are sold in Europe and Japan by other companies. The insect repellent pads of the Skeeter Eater device are flat and rectangular. The device has a flat bed, which is bridged over by a grid. A user slides a repellent pad onto the bed from an opening at one side of the grid and may retrieve it from a comparable opening at the opposite side of the bed. The liquid fuel devices generally require a user to pour fuel prior to using the device, with the consequent danger of spilling flammable liquids. Such spillage presents both a fire hazard and a mess, especially in devices that are lit with a match or other open flame.
Although these devices and methods exist in the art, being referred to by way of example only, the art is still in need of a safe and easy to use device that is not limited by the need to be plugged into an electrical receptacle, being instead entirely portable for use at any location desired. The art is also still in need of a combustion-heated device for volatilizing an active ingredient where that device requires no unguarded or accessible flame that could ignite flammable materials in the area and also operates with the adjustability, cleanliness, freedom from odor, and reliability associated with electrical devices.
U.S. Pat. No. 5,700,430 to Bonnema et al. and assigned to the same assignee as is the present invention overcomes a number of the deficiencies in the art, and its teachings are incorporated by reference herein. The Bonnema et al. patent describes a butane-using device for dispensing a volatile substance that heats a pad impregnated with insect repellent or the like in a manner much safer than the above-referenced Skeeter Eater. However, the device does not produce any light, and the use of a hydrocarbon-powered lamp in conjunction with the Bonnema et al. device requires two devices that use butane simultaneously, a scenario that inefficiently wastes butane and creates an unnecessarily large quantity of waste heat. Furthermore, unless the Bonnema et al. device is placed close to the light source, insects may still be attracted to the light source.